1.Field of the Invention
The invention relates to methods and devices for manufacturing a conduit for placing a target vessel in fluid communication with a source of blood, and more particularly placing a coronary vessel in fluid communication with a heart chamber containing blood.
2. Description of Related Art
Despite the considerable advances that have been realized in cardiology and cardiovascular surgery, heart disease remains the leading cause of death throughout much of the world. Coronary artery disease, or arteriosclerosis, is the single leading cause of death in the United States today. As a result, those in the cardiovascular field continue to search for new and improved treatments.
Coronary artery disease is currently treated by interventional procedures such as percutaneous transluminal coronary angioplasty (PTCA), coronary stenting and atherectomy, as well as surgical procedures including coronary artery bypass grafting (CABG). The goal of these procedures is to reestablish or improve blood flow through occluded (or partially occluded) coronary arteries, and is accomplished, for example, by enlarging the blood flow lumen of the artery or forming a bypass that allows blood to circumvent the occlusion. What procedure(s) is used typically depends on the severity and location of the blockage(s). When successful, these procedures restore blood flow to myocardial tissue that had not been sufficiently perfused due to the occlusion.
An alternative, recently proposed treatment places the target vessel in fluid communication with a heart chamber containing blood, for example, the left ventricle. Blood flows from the ventricle into a conduit that is in fluid communication with the target vessel. Some of the challenges associated with these procedures include delivering and deploying the conduit in the patient""s body, and in particular properly positioning the conduit with respect to the heart chamber and the target vessel.
The continued improvement and refinement of existing treatments and the search for new treatments are indicative of the significant effort that continues to be expended in order to develop better and more efficient ways of revascularizing the heart.
Accordingly, there is a need in the art for improved methods and devices that are capable of being used quickly, easily and in a repeatable manner to carry out cardiac revascularization successfully and economically. Consequently, there is a need in the art for methods and devices for manufacturing conduits that will meet one or more of these needs.
According to one embodiment of the invention, methods and devices are provided for manufacturing a conduit for use in placing a target vessel in fluid communication with a source of blood. One method includes steps of providing a biocompatible material suitable for use in delivering blood, and forming the biocompatible material into a conduit comprising first and second portions disposed transverse to each other and having lumens in fluid communication. The first conduit portion is formed with at least one inlet configured to be positioned in fluid communication with a heart chamber containing blood, and at least a part of the first conduit portion has sufficient rigidity to prevent collapse during myocardial contraction when disposed in or secured to myocardial tissue. The second conduit portion is formed with at least one outlet configured to be placed at least partially within the lumen of a target vessel in fluid communication with the vessel, and at least a part of the second conduit portion has sufficient resiliency to allow the second conduit portion to substantially conform to the contour of the target vessel.
Another method includes steps of providing a mold having a cavity configured to form a conduit including first and second portions disposed transverse to each other, wherein a conduit corresponding to the cavity is suitable for use in placing a source of blood in fluid communication with the lumen of a target vessel, placing a biocompatible moldable material in the mold cavity, subjecting the material to conditions that mold the material into a conduit having a desired configuration, and separating the mold and the conduit.
Another method includes step of providing a mold having a cavity including first and second portions disposed transverse to each other, positioning a mandrel in the mold cavity, the mandrel having first and second portions substantially corresponding to the first and second portions of the mold cavity, and forcing a moldable material into the mold cavity and around the first and second portions of the mandrel into the first and second portions of the mold cavity. The method further includes subjecting the material to conditions sufficient to set the material in a desired configuration, removing the mandrel from the mold, and separating the mandrel and the material to produce a conduit comprising first and second portions that are disposed transverse to each other and have lumens in fluid communication with each other.
Another method includes steps providing a mandrel including first and second portions disposed transverse to each other, the first and second portions of the mandrel defining at least one external surface corresponding to an interior surface of a desired conduit configuration, disposing a biocompatible moldable material on the external surface of the mandrel, subjecting the material to conditions that mold the material into a conduit having the desired configuration, and separating the conduit from the mandrel.
Still another method includes steps of forming biocompatible material into a conduit comprising first and second portions disposed transverse to each other and having lumens in fluid communication, forming the first conduit portion with at least one inlet configured to be placed in fluid communication with a heart chamber containing blood, and providing at least a part of the first conduit portion with sufficient rigidity to prevent collapse during myocardial contraction when disposed in or secured to myocardial tissue. The second conduit portion is formed with at least one outlet configured to be placed at least partially within the lumen of a target vessel in fluid communication with the vessel, and this step is carried out so as to form the first conduit portion with a full tubular configuration that extends substantially 360xc2x0 in cross-section, and the second conduit portion with a partial tubular configuration that extends less than 360xc2x0 in cross-section.
A mold constructed according to the invention includes a base defining a mold cavity, wherein the mold cavity has first and second portions configured to form a conduit including first and second portions, and wherein the first and second portions of the mold cavity are disposed transverse to each other to form a conduit with first and second conduit portions in fluid communication with each other and adapted to place the lumen of a target vessel in fluid communication with a heart chamber containing blood.
Another method according to the invention includes steps of providing first and second hollow members each of which has a lumen, forming an opening that extends into the lumen of the first hollow member, positioning one of the first and second ends of the second hollow member adjacent the opening in the first hollow member, and joining the one end of the second hollow member to the first hollow member with the lumens of the first and second hollow members sealed together in fluid communication.